These businesses pay expensive rent to be in a downtown vs. the boonies who gladly would let them build a sprawling corporate campus and pay no taxes. There are actual business decisions for burning that rent money downtown.

- Close to colleagues/network of other businesses in your industry downtown. Meetings can happen over lunch, or drinks after work. This is pretty advantageous for the employee; your next job could be just a block away and offered to you by the guy you see in the elevator every day.

- Close to transportation. Chances are, all the rail lines, bus lines, roads and highways all lead to downtown. A business located downtown can have workers from all over the metropolitan area. A location in the suburbs just gets workers who are able to drive to that suburbs, the infrastructure isn't there to move large amounts of people from around town to the suburbs. Moving businesses to suburbs introduces sprawl, which is bad for the environment, and also slowly bled every great American city after WWII as downtown became vacant (see Detroit).

At risk of blaming the commuter, I think a lot of this comes down to whether the non-commute option allows you not to own a car at all. Cars are expensive, like $700/mo expensive by some studies, and not having to have one (or worse, two) probably allows most families a very significant bump up in money able to go to their housing expenses.

I think for a lot of people the calculus is "well, I need a car no matter what (cost $Y), and because I have a car, my mortgage payment can be at most $X-$Y, and since I have a car anyway, I don't mind driving it for ten hours a week, so I might as well live way out in the boonies to maximize the amount of house I can get for $X-$Y."

But all of that unravels if you revisit the initial assumption that a car is necessary, and look at non-car housing options for $X. In many North American cities, a car really is necessary. But it's not everywhere, and it's getting better all the time.